If one thinks about the most important components of agriculture, soil tops the chart, for without soil, it is impossible to attain the scale of farming needed to meet the current and future demand of mankind. However, it is also one of the most neglected aspects of farming.
Soil erosion is one of the biggest threats to food security goals in India and the world. However, it is an invisible factor – though erosion has degraded one-third of the world’s soil moderately or more heavily, we may not see even an inch of it regaining in our lifetime, for it takes nearly 1000 years to form 1 cm of top soil, the most fertile layer. Erosion decreases the quality and availability of nutrients in the soil of a given area and thus prevents farmers from growing crops that not only fill our stomach but provide us with the right nutrition. Soil erosion can reduce crop yields by half and crops grown tend to be malformed, smaller in size and less nutritious. The economic toll of soil erosion is also huge – according to a study, the estimated global economic losses from soil erosion, due to lower soil fertility, crop yields and increased water consumption, is around USD 8 billion.
Reasons for soil quality erosion
The data collated by the National Bureau of Soil Survey and Land Use Planning in 2004 illustrated that out of the reporting area with 264.5 million hectare used for agriculture, forestry, pasture and other biomass production, more than 145 million hectare is degraded. Soil helps in filtering the underground water underground. Erosion affects the quality and quantity of water supply, especially in lowland areas where inadequately filtered water is being used for drinking, cooking food and more such activities. There are a few reasons for soil erosion of agricultural lands in India. The first is the natural wear and tear, caused by water and air. This is a common and age-old phenomenon, and the reason shore and desert forms vary according to the location and direction of water or wind flow. The second important factor is the increasingly poor agricultural practices. Very few farmers follow the traditional practices of intercropping or rotational cropping that allows soil to recover fertility before a fresh crop is sown. This gap is filled in with heavy use of fertilisers such as urea to maintain nitrogen (N) levels, and diammonium phosphate (DAP) and muriate of potash (MOP) for phosphorous (P) and potassium (K), respectively. This has led to a serious imbalance in the nutrient level of Indian agricultural land where the NPK ratio is 6.7:2.4:1, instead of the accepted 4:2:1. The practice of crop residue burning is also a part of the problem as profoundly contributes in depletion of Soil Organic matter (SOM). Along with excessive tillage and use of heavy machinery, dropping SOM levels further leads to poor soil structure and limited soil life.
Preventing soil erosion is easy
The current method of cultivation and preparing the land for it were derived from an industrialised Europe of the 18th century that focuses on increased yield with minimal effort. However, soil-friendly methods like no-till farming were in vogue for almost 10,000 years. Conventional tilling requires turning over the top 10 inches of soil to plant new seeds but in the process, relaxes and removes any plant matter that covered the soil, exposing it to the wind and water, and more likely to be eroded by these agents. It also kills microbes and insects, who are part of healthy soil biology. Rotating or alternating high-residue crops such as high residue-producing crops, such as wheat, barley, and corn along with low-residue ones such as lentils, peas, flax, soybeans, and sunflowers is another effective way to manage soil erosion and reduce it. Traditional farming practices such as polyculture are also helpful as they bring in plant diversity, enable vegetation cover of the soil and increases fertility. For example, a paddy farmer can garner all the benefits if they plant leguminous trees in the periphery of their paddy fields.
Soil has been The ancient Vedas recognized soil as basis of survival:
“Upon this handful of soil our survival depends. Care for it, and it will grow our food, our fuel, our shelter and surround us with beauty. Abuse it, and the soil will collapse and die, taking humanity with it.”
The great father of nation Mahatma Gandhi also reminds us:
"To forget how to dig the earth and tend the soil is to forget ourselves."
Protect soils – nurture humanity.
